In a long process of using a photovoltaic module for tens of years, there are often various opaque objects falling or stuck to the front of the module. Once there is a foreign matter, a hot-spot effect occurs. In this case, a diode of a protection component is conducted, a current flows through the diode, and heat is generated. As such a case occurs frequently, the diode is probably invalid before a warranty period ends. In this case, a function of protecting the module against the hot-spot effect is invalid, and the entire power station is endangered. Moreover, for a double-glass module, because glass is used at the back and edges have favorable sealing performance, a service life of the module can be prolonged to more than 40 years, but it is difficult for a connection box with a plastic base material to reach such a target service life. This problem can be resolved in two manners: change the material of the connection box, which inevitably causes a great increase in costs; or replace the connection box before a design life of the connection ends or when the connection box is invalid during use.
In the structure of a current connection box, a diode, a bus bar, and a conductive block are all immersed in solidified potting glue, to replace the connection box, the potting glue in the connection box needs to be removed and cleaned up. In this way, on the one hand, the bus bar may be broken off, and the potting glue on the bus bar is difficult to be removed, resulting in difficult welding of the bus bar or false welding when a new connection box is disposed, having great potential risks; on the other hand, a great deal of manpower and time needs to be consumed to replace the connection box, causing unnecessary waste. A defect in design of such a connection box is that the bus bar is located exactly above a leading leg of the diode, and the diode may be welded off or false-welded due to melting of a tin solder when the bus bar is welded, which easily causes a production defect.